Carbureter for internal-combustion engines.



P. D. LEE.

GARBURETER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED SEPT. 24, 1910.

998,355, Patented July 18, 1911.

f Fig.1. Z1 6 d2 h m JMM 611 /0 M7 y M? PHILIP DOUGLAS LEE, or LONDON, ENGLAND.

CARBURETER FOR INTERNAL-COMBUSTION ENGINES Specification of Letters Patent.

Patented July 18, 1911.

Application filed. September 24, 1910. Serial No. 583,554.

To all whom it may concern:

Be it known that I, PHILIP DOUGLAS LEE, a subject of His Majesty the King of Great Britain, residing at 300 St. James Court, Buckingham Gate, London, England, gentleman, have invented certain new and use- "ful Improvements in or Relating to Carbureters for Internal-Combustion Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to carburetors for internal combustion engines whereof the auxiliary air valve is opened by suction against spring resistance, and has for its object to insure that at all openings. of the throttle, irrespective of engine speed, the additional air required shall be supplied through the valve aforesaid in the correct and proper proportion, that is to say that at all engine speeds and all throttle openings the proportions of air and petrol constituting the mixture taken by the engine shall remain constant and substantially invariable.

Figure 1, is a sectional elevational view of a carbureter embodying my invention; Fig. 2 is a plan view, parts being shown in section, of the means for adjusting the tension of the tensioning element of the aux *iliary air valve; and Fig. 3 is a sectional plan view of a modified form of the invention.

It is obvious that in order to attain this result the spring resistance to the opening of the auxiliary air valve must be regulated in accordance with the opening of the throttle in such a manner that said spring resistance will be increased in direct proportion to the opening of the throttle, and vice versa since the spring resistance which permits the said valve to open to the extent required to pass the correct proportion of air when the throttle is fully open would clearly be too great were the throttle partially closed and the suction in consequence reduced. Means have'therefore to be proter automatically increases sai vided for regulating the said spring resistance to-suit the circumstances and hitherto independent hand regulation has sometimes been used, the judgment of the operator having tobe relied on for making the adjustment, and the system having the further disadvantage that an additional handle or control requires attention.

According to the present invention I provide means whereby the spring resistance to the opening of the said auxillary air valve is automatlcally regulated by the act of opening and closing the throttle valve, in such a manner that the openin of the latspring resistance, and vice versa. Thus the same movement of the pedal or other control which operates the throttle also effects the automatic regulation of the said spring resistance in the manner above'set forth.

It will be obvious that my invention as above outlined is susceptible of very considerable modifications in the manner of performing it, and I will now describe by way of example and with reference to the annexed drawings, two suitable embodiments of the invention.

Similar letters refer to corresponding parts in all the figures.

Referring to Fig. 1 which shows in sectional elevation an application of my invention to a carbureter of well known type, and tothe part plan view Fig. 2,;a indicates the throttle valve, 6 the inlet pipe for the mixture, c c pipes leading right and left from the throttle to the engine, and d an auxiliary air valve of known construction provided with the usual dashpot (2, said valve being held closed by a light spring 6 located and held in com ression between a washer f on .the valve splndled and nut g rotatable on Now according to my invention I cause nected with the.arm g extending from the nut g aforesaid. It will thus be seen that the same movement of the pedal or other control .which actuates the throttle valve will also effect the automatic regulation of the resistance of'the spring e to the opening by suction of the auxiliary air valved, in such a manner that opening of the throttle will increase the spring resistance and vice versa. Adjustment of the effective length of the connecting rod Z may be obtained by the adjusting nuts I on said rod; and by providing a series of holes m in the arm of lever i for the reception of the end of the connecting rod Z, the speed of motion of the latter relatively to that of the throttle operating rod a may also be regulated. n indicates a suitable joint which may conveniently be placed in the connecting rod Z. An adjustable-stop may be provided to arrest further movement of the nut y when the minimum desirable spring resistance is reached.

In the embodiment of the invention shown in Fig. 3, which illustrates in sectional elevation an application thereof to another form of carbureter, the automatic regulation in the manner above set forth of the spring resistance to the opening by suction of the air valve (2 is effected as follows The axes of the throttle valve a and the auxiliary air valve d are here arranged in line and between the valves is inter posed the spring e. When the throttle is moved upward to open it, the spring e engages the valve (1, its compression increas-- mg in direct proportion to the opening of the throttle, whereby the spring resistance to the opening of the air valve (2 is automatically increased. As shown the spring e is slightly separated from the air valve (1 when the throttle is closed, and at the commencement of the opening movement the spring resistance to the opening of the air valve'is provided by the spring e only, which has a very light pull, say about 1% ounce; continuation of the opening movement brings the spring e'into action and adds its resistance to that of spring e. The spring e may, however, be entirely dispensed with if preferred, and reliance for spring resistance to the opening of the valve (2 a. a I 998,355

placed solely on the spring e, which in this case would be lengthened so as to be in slight compression between the throttle valve a and the air valve d when the throttle is fully closed.

In conclusion I would observe that I do not confine or limit myself to the particular constructions described and illustrated in the drawings since the same may obviously be considerably varied without in any way departing from my invention.

What I claim and desire to secure by Letters Patent of the United States is 1. In a carbureter for internal combustion engines, the combination with a throttle valve and means for operating the same, of a spring influenced auxiliary air valve adapted to be opened by engine suction; and means whereby said throttle valve may be opened and the resistance to opening of said air valve proportionately increased, or said throttle valve may be closed and the resistance to opening of said air valve proportionately decreased, whereby the proportions of the combustible mixture for engine operation are kept constant at all engine speeds and throttle openings.

2. In a carbureter for internal combustion engines, the combination with a throttle valve and means for operating the same, of an auxiliary air valve ada ted to be opened by engine suction, a spring tending to normally hold said auxiliary valve to its seat and means whereby said throttle valve may be opened and the resistance to opening of said air valve proportionately increased, or said throttle valve may be closed and the resistance to opening of said air valve proportionately decreased, whereby the proportions of the combustible mixture for engine operation are kept constant at all engine speeds and throttle openings.

3. In a carbureter for internal combustion engines, the combination with a throttle valve having an elongated operating rod, of an auxiliary air valve adapted to be opened by engine suction, a spring encircling the stem of said auxiliary valve, a threaded'sleeve embracing said stem, a nut movable on said sleeve and adapted by its movement to vary the tension of said spring, an operating rod for said nut, and a lever engaging both said rods and adapted when moved to concurrently move said throttle valve and said nut.

4. In a carbureter for internal combustion engines, the combination with a throttle valve having an elongated operating rod, of an auxiliary air valve adapted to be opened by engine suction, a spring encircling the stem of said auxiliary valve, a threaded sleeve embracing said stem, a nut movable on said sleeve and adapted by its movement to vary the tension of said spring, a jointed In testimony whereof I have hereunto set plperatingfrolg; for saiddnpt, and a lever my hand. in the presence of two witnesses.

aving a or at one en or enga in the" operating rod of the throttle valve a hd hav- PHILIP DOUGLAS 5 i-ng a series of holes in its other end for Witnesses:

reception of one end of the jointed operat PERCY MUNLEY, ing rod of the said nut. FREDK.\ RHODES. 

